Relationship between tumorigenesis of human lung squamous carcinoma tissues in nude mice and the expression level of Ki-67 / 肿瘤

ABSTRACT

Objective: To establish the transplanted tumor models of human lung squamous cell carcinoma in nude mice, and to explore the relationship between the tumorigenicity of carcinoma tissues and Ki-67 expression level. Methods: Lung squamous cell carcinoma tissues were collected from 21 patients who underwent surgical resection at the Department of Thoracic Surgery of Anhui Provincial Hospital from August 2013 to January 2014. Lung carcinoma tissues were subcutaneously implanted into nude mice within 1 hour after surgical resection. The tumorigenicity of transplanted carcinoma tissues was observed, and the characteristics of patients with primary tumors that could form xenograft tumor (XG group) and couldn't form xenograft tumor (no-XG group) were compared retrospectively. The expressions of p63, cytokeratin 5/6 (CK5/6), thyoid transcription factor-1 (TTF-1) and Ki-67 were detected by immunohistochemistry, and the expression level of Ki-67 was semi-quantitatively analyzed by H-score method. The mutation status at the exons 18-21 of epidermal growth factor receptor (EGFR) gene was examined by amplification refractory mutation system (ARMS)-PCR. Results: Twelve (57.1%) xenograft models were succsessfully established after total 21 lung squamous cell carcinoma tissues were implanted into nude mice. The tumorigenicity of lung squamous cell carcinoma tissues in nude mice was correlated with differentiation (Z = -2.821, P = 0.005) and size (Z = -2.809, P = 0.005) of primary tumor in patients. High homogeneity of the expressions of p63, CK5/6, TTF-1 and Ki-67 as well as EGFR gene mutation status was found between xenograft tumors in nude mice and the lung squamous cell carcinoma tissues from the patients. The average H-score of the expression level of Ki-67 in XG group was 2.76±0.54, which was significantly higher than that in no-XG group (1.37±0.77) (t = 4.855, P = 0.001). Conclusion: The xenotransplantation models of patient-derived lung squamous cell carcinoma in nude mice were successfully established. Their tumorigenesis may be correlated with the expression level of Ki-67 in lung squamous cell carcinoma. This model system retains the basic biological characteristics of human lung squamous cancer, suggesting that it may provide a perfect platform for the research on human lung squamous cell carcinoma.